Sterile surgical drape with inherently stable tracking reference array cover

Abstract

The invention relates to a sterile surgical drape comprising a cover portion for a tracking reference array, wherein at least a part of the cover portion is formed inherently stable and has a form adapted to accommodate multiple tracking markers of a tracking reference array for computer-assisted surgery. Further, it relates to a surgical draping system and a medical navigation method using such a drape.

The invention claimed is: 
     
       1. A sterile surgical drape comprising a cover portion for a tracking reference array having a support structure and a plurality of tracking markers extending from the support structure, wherein at least a part of the cover portion is formed inherently stable such that the part is rigid and has a form adapted to accommodate the support structure and the tracking markers of the tracking reference array for computer-assisted surgery, wherein parts of the cover portion that cover the tracking markers are transparent to allow for tracking of the markers, wherein the cover portion has areas with minimized retro-reflection characteristics that have a surface or surface structure that avoids reflections, and wherein the surface or surface structure includes at least one of a macro scale structure, a micro scale structure, a painting, or an adhesive material. 
     
     
       2. A sterile surgical drape according to  claim 1 , wherein the cover portion is made of a rigid plastic material formed or thermoformed to fit the contour of the tracking reference array. 
     
     
       3. A sterile surgical drape according to  claim 1 , wherein the cover portion is adapted to cover the upper portion of the entire tracking reference array. 
     
     
       4. A sterile surgical drape according to  claim 1 , wherein the parts of the cover portion that cover the tracking markers are transparent clear areas that are highly light-permeable or have high optical properties. 
     
     
       5. A sterile surgical drape according  claim 1 , wherein:
 the macro scale structure comprises indentations, protrusions or dimples, and/or 
 the micro scale structure is created by a surface treatment, and/or 
 the painting has retro-reflection-minimizing colour on the surface, and/or 
 adhesive material has minimal retro-reflection. 
 
     
     
       6. A sterile surgical drape according to  claim 1 , wherein, on the surface of the cover portion, calibration recesses or reference points are formed at positions that mirror or correspond to the position of respective recesses or points on the tracking reference array, in order to provide separate calibration or reference locations associated to the sterile surgical drape. 
     
     
       7. A sterile surgical drape according to  claim 1 , wherein, on the surface of the cover portion, one or more additional functional areas are marked or designated. 
     
     
       8. A sterile surgical drape according to  claim 7 , wherein the one or more additional functional areas include:
 retro-reflective tracking markers; 
 device identification labels; or 
 remote control areas or labels in a form of symbols, text markers or colour codes, recognizable for a medical navigation system and creating commands when interacting with a navigated instrument. 
 
     
     
       9. A sterile surgical drape according to  claim 1 , further comprising a flexible outer drape portion joining or encompassing the cover portion at a joining area. 
     
     
       10. A sterile surgical drape according  claim 9 , wherein the sterile surgical drape is adapted to be folded into a pack having an orientation guide visible on one side and showing the orientation of the cover portion of the drape to the user. 
     
     
       11. A sterile surgical drape according to  claim 1 , wherein the cover portion has a lower surface, and wherein one or more holders are provided on the lower surface to engage with the tracking reference array in order to fasten the cover portion thereon. 
     
     
       12. A surgical draping system comprising at least first and second sterile surgical drapes in accordance with  claim 1 , wherein an overlying cover portion of the first sterile surgical drape is adapted to snugly accommodate an underlying cover portion of the second sterile surgical drape. 
     
     
       13. A system according to  claim 12 , wherein the overlying cover portion comprises an identification marker or label uniquely identifying the identification marker or label or distinguishing the identification marker or label from the underlying cover portion, by positional or symbolic information to be received and processed by a medical navigation system. 
     
     
       14. The sterile surgical drape according to  claim 1 , wherein the support structure includes a plurality of arms, and wherein one of the plurality of tracking markers is at an end of each of the plurality of arms. 
     
     
       15. The sterile surgical drape according to  claim 14 , wherein the cover portion has a base portion and a raised portion extending upward from the base portion, the raised portion adapted to accommodate the plurality of arms and the tracking markers.